This invention relates to a composite tube for a gun barrel and more particularly to a composite tube including carbon fibers and a resin matrix material, with breech and muzzle pieces attached to the gun barrel by an adhesive or threads and enclosing the resin matrix material, so that vibrations in the barrel are reflected into the resin matrix material by the breech and muzzle pieces.
Composite gun barrels are desirable because they permit the construction of lightweight firearms. A composite barrel such as one constructed from a tube made of carbon fiber and epoxy resin materials, however, typically lacks sufficient stiffness to maintain its integrity for accurate reproducible firing. Even when the composite barrel includes an inner tubular liner, a firearm having such a composite barrel tends to be less accurate than a fiream having a conventional barrel.
A composite tube and method of manufacture for a gun barrel is disclosed in U.S. Pat. No. 5,600,912, herein incorporated by reference, and invented by the same inventor. While the composite tube there disclosed has certain advantages over the prior art, the inventor has found that the improvements disclosed and claimed herein add greatly to the accuracy of fire of the gun barrel.
More particularly, the receiver of a firearm in combination with a steel barrel acts like a bell. Since the steel barrel is of one homogeneous material, when a cartridge is fired, the entire system vibrates at a particular frequency. Such vibrations are generally detrimental to the performance of the barrel.
Such vibrations travel down the length of the barrel as soon as the trigger is released and the cocking piece strikes the primer of the cartridge, due to metal-to-metal contact in on all-metal structure. Upon ignition, these vibrations or harmonics increase. As the vibrations travel down the barrel, they cause the barrel to vibrate at a group of frequencies. In the past, part of the art of gunsmithing was to achieve appropriate barrel length to be consistent with the wavelength of these frequencies to minimize barrel vibration.
Barrel vibration causes a bullet to be deflected from the target line, resulting in inaccuracy of fire.
U.S. Pat. No. 5,600,912 disclosed a barrel which helps to eliminate these harmonic vibrations by absorbing the vibrations into a carbon fiber material oriented longitudinally along the barrel. However, the invention disclosed there does not fully eliminate harmonics which reach the muzzle and breech pieces, because the muzzle and breech pieces are not tightly integrated with the carbon fiber material. Also, the carbon fiber material in the '912 patent is not compressed sufficiently to produce optimum fiber density in the resin matrix material.
There is a need for a composite tube for a gun barrel which overcomes the above-discussed deficiencies.